Not bad!
Could use some more enemies perhaps. I'm not sure if there were more, but the game got repetitive after about 15 enemies in. The diversity in guns were cool and the rage meter was a fun touch.
If you ever consider changing things, maybe add more enemies and different levels/background (from what I saw, there was only one). Also, my biggest criticism was that unless you broke both boxes, the game didn't start. I broke only the top box and wandered around the level for a few minutes before anything happened. Consider not letting the player progress unless both boxes are broken.